export default {
  // 为当前模块开启命名空间
  namespaced: true,
  
  // 模块的 state 属性
  state: () => ({
    // 购物车的数组,用来储存购物车中每个商品的信息对象
    // 我们规定每个商品的信息对象,都包含如下6个属性
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  
  mutations: {
    addToCart(state, good) {
      const findResult = state.cart.find(x => x.goods_id === good.goods_id)
      if(!findResult) {
        state.cart.push(good)
      }else{
        findResult.goods_count++
      }
      
      this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state) {
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    updateGoodsStatus(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult) {
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage')
      }
    },
    updateGoodsCount(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult) {
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    deleteGoodsById(state, goods) {
      state.cart = state.cart.filter(x => x.goods_id !== goods.goods_id)
      this.commit('m_cart/saveToStorage')
    },
    updateAllGoodsState(state, newState) {
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  
  getters: {
    // 购物车中所有商品的总数量
    total(state) {
      // let c = 0
      // state.cart.forEach(goods => c += goods.goods_count)
      // return c
      return state.cart.reduce((total, item) => total += item.goods_count, 0)
    },
    // 购物车中已勾选商品的数量
    checkedCount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => {return total += item.goods_count}, 0)
    },
    checkedGoodsAmount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => {return total += item.goods_count * item.goods_price }, 0).toFixed(2)
    }
  }
}